This disclosure relates in general to field-programmable logic chip or circuit (FPLC) and, but not by way of limitation, to FPLC used in traffic processing such as cryptographic processing.
Programmable circuitry is common in logic design, but achieving the level of security and high-assurance desired by the governments, individuals and certain businesses has been difficult. Programmability is seen as a risk to achieving security and high-assurance. This is especially true when programmability is utilized in the field. One could imagine the programmability feature being used to cause the FPLC to operate in a mode that would not have the required security.
Cryptographic circuitry can fail or be compromised. Where such a circuit enters an error mode, there is no recovery. Failure can result in insecure functioning that is not desirable. The cryptographic circuit can erase keys to prevent further activity. Even without keys, the cryptographic circuit can perform in undesirable modes when malfunctioning. With programmability, the risk of these malfunctions is greater.
FPLCs have many advantages over fixed circuitry, but cost is generally not one of the advantages. Various images and soft cores are loaded into FPLCs. The size of the FPLC is chosen to accommodate all the images needed for a given design. When smaller or fewer FPLCs are possible, the costs of producing a unit decreases.